package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.util.BooleanUtil;
import cn.hutool.core.util.StrUtil;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.hmdp.dto.Result;
import com.hmdp.dto.ScrollResult;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Blog;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.BlogMapper;
import com.hmdp.service.IBlogService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IFollowService;
import com.hmdp.service.IUserService;
import com.hmdp.utils.SystemConstants;
import com.hmdp.utils.UserHolder;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.ZSetOperations;
import org.springframework.stereotype.Service;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.concurrent.atomic.LongAdder;
import java.util.stream.Collectors;

import static com.hmdp.utils.RedisConstants.BLOG_LIKED_KEY;
import static com.hmdp.utils.RedisConstants.FEED_KEY;


@Service
public class BlogServiceImpl extends ServiceImpl<BlogMapper, Blog> implements IBlogService {

    @Autowired
    private IUserService userService;

    @Autowired
    private StringRedisTemplate stringRedisTemplate;

    @Autowired
    private IFollowService followService;
    @Override
    public Result queryBlogById(Long id) {
        // 1.查询blog
        Blog blog = getById(id);
        if (blog == null){
            return Result.fail("播客不存在");
        }
        // 2.查询blog有关的用户
        queryBlogUser(blog);
        // 3.查询blog是否被点赞了
        isBlogLiked(blog);
        return Result.ok(blog);
    }

    private void isBlogLiked(Blog blog) {
        // 1.获取登录信息
        UserDTO user = UserHolder.getUser();
        if (user == null){
            // 用户未登录，无需查询是否点赞
            return;
        }
        Long userId = user.getId();
        // 2.判断当前用户是否点赞
        String key = "blog:liked:" + blog.getId();
//        Boolean isMember = stringRedisTemplate.opsForSet().isMember(key, userId.toString());
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
//        blog.setIsLike(BooleanUtil.isTrue(isMember));
        blog.setIsLike(score != null);
    }

    @Override
    public Result queryHotBlog(Integer current) {
        // 根据用户查询
        Page<Blog> page = query()
                .orderByDesc("liked")
                .page(new Page<>(current, SystemConstants.MAX_PAGE_SIZE));
        // 获取当前页数据
        List<Blog> records = page.getRecords();
        // 查询用户
        records.forEach(blog -> {
            this.queryBlogUser(blog);
            this.isBlogLiked(blog);
        });
        return Result.ok(records);
    }

    @Override
    public Result likeBlog(Long id) {
        // 1.获取登录信息
        UserDTO user = UserHolder.getUser();
        Long userId = user.getId();
        // 2.判断当前用户是否点赞
        String key = BLOG_LIKED_KEY + id;
//        Boolean isMember = stringRedisTemplate.opsForSet().isMember(key, userId.toString());
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
//        if (BooleanUtil.isFalse(isMember)){
        if (score == null){
            // 3.未点赞，可以点赞
            // 3.1.数据库点赞数 + 1
            boolean  isSuccess = update().setSql("liked = liked + 1").eq("id", id).update();
            // 3.2.保存用户到set集合中
            if (isSuccess){
//                stringRedisTemplate.opsForSet().add(key,userId.toString());
                stringRedisTemplate.opsForZSet().add(key,userId.toString(),System.currentTimeMillis());
            }
        }else {
            // 4.如果已点赞，取消点赞
            // 4.1.数据库点赞数 - 1
            boolean  isSuccess = update().setSql("liked = liked - 1").eq("id", id).update();
            // 4.2.用户从redis中删除
            if (isSuccess){
//                stringRedisTemplate.opsForSet().remove(key,userId.toString());
                stringRedisTemplate.opsForZSet().remove(key,userId.toString());
            }
        }
        return Result.ok();
    }

    @Override
    public Result queryBlogLikes(Long id) {
        String key = BLOG_LIKED_KEY + id;
        // 1.查询top5点赞用户 zrange key 0 4
        Set<String> range = stringRedisTemplate.opsForZSet().range(key, 0, 4);
        if (range == null || range.isEmpty()){
            return Result.ok(Collections.emptyList());
        }
        // 2.解析其中用户id
        List<Long> ids = range.stream().map(Long::valueOf).collect(Collectors.toList());
        // 3.根据用户id的查询用户 where id in (5 , 1) order by field(id , 5, 1)
        String idStr = StrUtil.join(",", ids);
        List<User> users = userService.query()
                .in("id",ids)
                .last("ORDER BY FIELD(id ," + idStr + " )").list();
        List<UserDTO> userDTOS = users.stream().map(user -> BeanUtil.copyProperties(users, UserDTO.class)).collect(Collectors.toList());
        // 4.返回

        return Result.ok(userDTOS);
    }

    @Override
    public Result saveBlog(Blog blog) {
        // 1.获取登录用户
        UserDTO user = UserHolder.getUser();
        blog.setUserId(user.getId());
        // 2.保存探店博文
        boolean isSuccess = save(blog);
        if (!isSuccess){
            return Result.fail("新增笔记失败");
        }
        // 3.查询笔记作者的所有粉丝 select * from follow where follow_user_id = ?
        List<Follow> follows = followService.query().eq("follow_user_id", user.getId()).list();
        // 4.推送笔记id给所有粉丝
        for (Follow follow : follows) {
            // 4.1.获取粉丝id
            Long userId = follow.getUserId();
            // 4.2.推送
            String Key = FEED_KEY + userId;
            stringRedisTemplate.opsForZSet().add(Key,blog.getId().toString(),System.currentTimeMillis());
        }
        // 5.返回id
        return Result.ok(blog.getId());
    }

    @Override
    public Result queryBlogOfFollow(Long max, Integer offset) {
        // 1.获取当前用户
        Long userId = UserHolder.getUser().getId();
        // 2.查询收件箱 ZREVRANGEBYSCORE Key max min LIMIT offset count
        String Key = FEED_KEY + userId;

        Set<ZSetOperations.TypedTuple<String>> typedTuples = stringRedisTemplate.opsForZSet()
                .reverseRangeByScoreWithScores(Key, 0, max, offset, 2);
        // 3.非空判断
        if (typedTuples == null || typedTuples.isEmpty()){
            return Result.ok();
        }
        // 4.解析数据:blogId、minTime（时间戳）、offset
        List<Long> ids = new ArrayList<>(typedTuples.size());
        long minTime = 0;
        int os = 1;
        for (ZSetOperations.TypedTuple<String> typedTuple : typedTuples) {
            // 4.1.获取id
            String idStr = typedTuple.getValue();
            ids.add(Long.valueOf(idStr));
            // 4.2。获取分数
            long time = typedTuple.getScore().longValue();
            if (time == minTime){
                os ++;
            }else {
                minTime = time;
                os = 1;
            }
        }
        // 5.根据id查询Blog
        String idStr = StrUtil.join(",", ids);
        List<Blog> blogs = query().in("id", ids).last("ORDER BY FIELD(id," + idStr + ")").list();

        for (Blog blog : blogs) {
            //5.1.查询blog有关的用户
            queryBlogUser(blog);
            //5.2.查询blog是否被点赞
            isBlogLiked(blog);
        }


        // 6.封装返回
        ScrollResult r = new ScrollResult();
        r.setList(blogs);
        r.setMinTime(minTime);
        r.setOffset(os);
        return Result.ok(r);
    }

    private void queryBlogUser(Blog blog) {
        Long userId = blog.getUserId();
        User user = userService.getById(userId);
        blog.setName(user.getNickName());
        blog.setIcon(user.getIcon());
    }
}
